Stress field evaluation for a propagating crack in a thin glass plate

An instantaneous phase-stepping technique using a CCD camera equipped with a pixelated micro-retarder array is applied to the study of quasi-static crack growth in a quenched thin glass plate. The distributions of the principal direction as well as the principal stress diference around a growing crack tip are obtained by instantaneous phase-stepping photoelasticity. Then, not only the mixed-mode stress intensity factors but also the T-stress are evaluated from the distribution of the principal stress difference, and they are validated using the reconstructed phase maps. By applying the proposed method to the sucsessive images, the time-variations of the fracture mechanics parameters are evaluated quantitatively. Results show that the proposed instantaneous phase-stepping technique is effective for the study of the crack growth behavior in a thin glass plate.